dtrace_udp — a DTrace provider for tracing events related to the UDP protocol

       The pktinfo_t  argument  is  currently  unimplemented  and  is  included  for  compatibility  with  other
       implementations of this provider.  Its fields are:

             uintptr_tpkt_addr  Always set to 0.

       The  csinfo_t  argument  is  currently  unimplemented  and  is  included  for  compatibility  with  other
       implementations of this provider.  Its fields are:

             uintptr_tcs_addr  Always set to 0.

             uint64_tcs_cid    A pointer to the structinpcb for this packet, or NULL.

             pid_tcs_pid       Always set to 0.

       The ipinfo_t argument contains IP fields common to both IPv4 and IPv6 packets.  Its fields are:

             uint8_tip_ver       IP version of the packet, 4 for IPv4 packets and 6 for IPv6 packets.

             uint32_tip_plength  IP payload size.  This does not include the size of  the  IP  header  or  IPv6
                                  option headers.

             stringip_saddr      IP source address.

             stringip_daddr      IP destination address.

       The  udpsinfo_t argument contains the state of the UDP connection associated with the packet.  Its fields
       are:

             uintptr_tudps_addr  Pointer to the structinpcb containing the IP state for the associated socket.

             uint16_tudps_lport  Local UDP port.

             uint16_tudps_rport  Remote UDP port.

             stringudps_laddr    Local IPv4 or IPv6 address.

             stringudps_raddr    Remote IPv4 or IPv6 address.

       The udpinfo_t argument is the raw UDP header of the packet, with all fields in host  order.   Its  fields
       are:

             uint16_tudp_sport      Source UDP port.

             uint16_tudp_dport      Destination UDP port.

             uint16_tudp_length     Length of the UDP header and payload, in bytes.

             uint16_tudp_checksum   A  checksum  of  the  UDP  header  and  payload,  or  0  if no checksum was
                                     calculated.

             structudphdr*udp_hdr  A pointer to the raw UDP header.

       This manual page was written by Mark Johnston <markj@FreeBSD.org>.

Debian                                           August 1, 2018                                    DTRACE_UDP(4)

       This provider is compatible with the udp provider in Solaris.

       The  DTrace  udp  provider  allows  users  to  trace  events  in the udp(4) protocol implementation.  The
       udp:::send() probe fires whenever the kernel prepares to transmit a UDP packet, and  the  udp:::receive()
       probe  fires  whenever  the  kernel  receives  a  UDP  packet,  unless  the UDP header is incomplete, the
       destination port is 0, the length field is invalid, or the checksum is wrong.   The  arguments  to  these
       probes  can  be  used  to  obtain  detailed information about the IP and UDP headers of the corresponding
       packet.

       The following script counts transmitted packets by destination port.

             udp:::send
             {
                     @num[args[4]->udp_dport] = count();
             }

       This script will print some details of each UDP packet as it is sent or received by the kernel:

             #pragma D option quiet
             #pragma D option switchrate=10Hz

             dtrace:::BEGIN
             {
                     printf(" %10s %36s    %-36s %6s\n", "DELTA(us)", "SOURCE",
                         "DEST", "BYTES");
                     last = timestamp;
             }

             udp:::send
             {
                     this->elapsed = (timestamp - last) / 1000;
                     self->dest = strjoin(strjoin(args[2]->ip_daddr, ":"),
                          lltostr(args[4]->udp_dport));
                     printf(" %10d %30s:%-5d -> %-36s %6d\n", this->elapsed,
                         args[2]->ip_saddr, args[4]->udp_sport,
                         self->dest, args[4]->udp_length);
                     last = timestamp;
             }

             udp:::receive
             {
                     this->elapsed = (timestamp - last) / 1000;
                     self->dest = strjoin(strjoin(args[2]->ip_saddr, ":"),
                          lltostr(args[4]->udp_sport));
                     printf(" %10d %30s:%-5d <- %-36s %6d\n", this->elapsed,
                         args[2]->ip_daddr, args[4]->udp_dport,
                         self->dest, args[4]->udp_length);
                     last = timestamp;
             }

/usr/lib/dtrace/udp.d  DTrace type and translator definitions for the udp provider.

       The udp provider first appeared in FreeBSD 10.0.

       dtrace_udp — a DTrace provider for tracing events related to the UDP protocol

dtrace(1), dtrace_ip(4), dtrace_sctp(4), dtrace_tcp(4), dtrace_udplite(4), udp(4), SDT(9)

udp:::receive(pktinfo_t*, csinfo_t*, ipinfo_t*, udpsinfo_t*, udpinfo_t*);

       udp:::send(pktinfo_t*, csinfo_t*, ipinfo_t*, udpsinfo_t*, udpinfo_t*);